Note: This article includes a sidebar "Preserving the Fire Scene:
Tips From Law Enforcement" by George A. Wendt.

Abstract: Fire suppression forces have four basic functions with
respect to a fire scene: observation, recognition, preservation and notification.
Firefighters should be able to note the various circumstances of the scene,
recognize those which represent evidence, protect those materials and then
notify the incident commander to ensure their proper collection and documentation.

The activities associated with suppression and overhaul can be damaging
to the investigation. Crews should avoid causing unnecessary damage when
using hoses, collapsing walls, breaking windows and pulling ceilings. When
possible, caution should be used in straight-stream applications, especially
at the base of the fire, which may be the point of origin. Hoses can move,
damage and destroy evidence. Excessive water can dilute combustible or flammable
liquids, resulting in false negative tests for the presence of an ignitable
liquid. Also, excessive standing water will prevent an investigatorís
access to potential fire patterns. Ideally, water should be drained in a
fashion that wonít impact the scene.

Excessive overhaul prior to the investigatorís examination of
the scene should be avoided. Ideally, the investigator should be present
and should supervise overhaul.

The investigator will want an opportunity to view the contents of the
house or room intact in order to properly reconstruct the scene. Also, firefighters
should avoid moving or turning any knobs or switches until their conditions
can be documented.

Use of power tools must be controlled, and prohibited near a location
where an ignitable liquid is suspected. All refueling should occur away
from the scene so that the fuel will not be later misconstrued as evidence.
Firefighters can unknowingly contaminate a scene simply by walking through
with ignitable liquid residue on their boots or tools.

Access to the scene should be limited to only the necessary personnel.